Continuity
gaps commonly occur
because scenes that we see in a certain order on
the screen are not necessarily shot in that
order. Parts of a scene may have to be reshot
afterwards and someone has to be responsible for
making sure that the positions of the props,
actors, clothing, mud, etc. are the same as in
the other shots. One little mistake and you might
have someone's jacket open in one shot, then
closed, then open again. Another continuity-type
gaff is when a character's personal details don't
remain constant (e.g. a sibling's name changes
from episode to another). Here are the ones we
come across so far:

When
Anna Lacey first arrives in the Valley,
she says that her only brother
"Ross" is backbacking around
Malaysia. However, when her brother
arrives for a visit a few months later,
his name has suddenly changed to
"Alec".